1. Field of the Invention
The present invention relates to a method for enabling the use of a consumable unit containing a consumable medium in a consumption device of a consumption arrangement, in particular a franking machine, in which in a first transmission step a first item of authorization information assigned to the consumable unit is transmitted by a data processing unit of the consumption arrangement via a communications network to a remote data center and in a first verification step in the data center a verification of the first item of authorization information takes place. In an authorization step in the data center as a function of the outcome of the first verification step a second item of authorization information assigned to the consumable unit is generated, which, in a second transmission step, is transmitted via a communications network to the data processing unit. In a second verification step, a verification takes place in the data processing unit of the second item of authorization information, wherein then in an enabling step in the data processing unit as a function of the outcome of the second verification step enabling the use of the consumable unit in the consumption device takes place. Further, in an accounting step as a function of the outcome of the first verification step and/or the second verification step accounting takes place for enabling the use of the consumable unit in the consumption device. The invention also relates to a corresponding arrangement for performing the method according to the invention and a data processing device that constitutes a component of this arrangement.
2. Description of the Prior Art
In a large number of applications, in which a physical representation of certain data (for example the printing out of data or similar) is generated, consumable materials are used for the generation of this physical representation, having certain properties, in order to guarantee a specified quality of the representation and/or optionally in conjunction with other features of the representation to prove the authenticity of the data reproduced or the authorization to generate the reproduction. Thus for example in modern franking machines as a rule special inks or toners specified by the postal service concerned are used in order to generate a validate franking imprint. The inks or toners used can also have certain security features that are invisible to the naked eye (such as for example fluorescent particles or similar).
In order to ensure that in connection with such a reproduction exclusively authorized consumable materials are used, a number of methods are known which should guarantee that only authorized consumable units (for example ink cartridges, ribbon cartridges, toner cartridges, etc.) are enabled for use in the consumption devices concerned.
Inter alia, in a number of methods applied locally in the franking machine, as known for example from EP 1 237 725 B1, authorization information stored in a memory of the consumable unit is verified in the franking machine, for example a digital signature of the manufacturer of the consumable unit is verified via specific information assigned to the consumable unit. Only if this verification is successful is the use of the consumable unit enabled. Otherwise printing is disabled. Similar methods are known from EP 1 132 868 A1 and EP 0 875 862 A2.
In other methods such as for example those known from EP 1 103 924 B1, a data center compares a code word sent by a franking machine via a communications network with a list of valid code words available in the data center. If this verification is unsuccessful, counter measures including disablement of the franking machine for use of the consumable unit can be initiated. A similar method is also known from DE 100 23 145 A1. In a further similar method, which is known from EP 1 103 925 B1, the franking machine holds a list of valid code words for the comparison.
Finally, from EP 1 103 925 A1 a generic method is known in which following use of an authorized consumable unit for a specific number of imprints further use of the franking machine is inhibited, even if sufficient ink is left for continued usage. Further use of the remaining ink is made possible, however, if in an enabling process in the interaction between the franking machine and a data center, against a corresponding payment by the user in an accounting process, a corresponding enablement takes place.
Common to all these methods is that correspondingly high effort is necessary in order to ensure that in the consumption device only authorized consumable units are used. This results in comparatively high costs for the individual consumable unit. Here in addition to some extent there is only limited protection, if any, against the use of pirate products or of previously authorized consumable units that have been refilled by third parties. Such unauthorized consumable units are typically sold at considerably lower prices than authorized consumable units, so that in this regard the economic pressure to achieve greater security increases further and the costs are forced up.
Thus in the memory known from EP 1 103 925 A1 of the consumable unit in fact the consumption or the residual quantity left is detected and the use of the consumable unit is inhibited as soon as a certain residual quantity is reached. In many cases, however, it is possible to manipulate the memory of the consumable unit. As a counter measure to this, memories with write once memory areas can be used although these drive up the costs. In addition third parties may try to exchange the “used” memory for a possibly even structurally identical “unused memory”. Here again various counter measures can be taken, although these again push up the costs.